On the Crimea-Texas project "Surface abundances of light elements for a large sample of early B-type stars".


  • L. S. Lyubimkov Crimean Astrophysical Observatory, Ukraine



Ключові слова:

stars, abundances, fundamental parameters


A significant part of the project is already implemented. Actually, high-resolution spectra of more than 100 early B stars were obtained. A number of basic parameters was determined including the effective temperatures Teff , surface gravities log g, masses M, ages t etc. A detailed non-LTE analysis of HeI lines was effected to find the helium abundance He/H, microturbulent parameter Vt and rotational velocity v sin i . Relations between He/H and Vt , from the one hand, and M, t/tms and v sin i , from the other hand, were constructed. It was confirmed that there is the helium enrichment during the MS phase, which correlates with the masses M and rotational velocities v sin i . It is necessary to note that from the outset we tried to get a highest accuracy on each stage of this work.

At present we are implementing a last stage of the project, i.e. an analysis of CII, NII and OII lines on the basis of non-LTE computations. Our goal is an accurate determination of the C, N and O abundances and a search for correlations with M, t/tms and v sin i.


ESA, 1997, The Hipparcos and Tycho Catalogues, ESA SP-IZOO. ESA, Noordwiflc.

Heger A., Langer N., 2000, ApJ., 544, 1016.

Hoffleit D., Warren W.H., Jr, 1991, The Bright Star Catalogue, 5th revised edn. ADS, Strasbourg (electronic version).

Kurucz K.L., 1993, CD-ROM 13.

Lyubimkov L.S., 1975, Pis'ma Astron. Zh., 1, #11, E.

Lyubimkov L.S., 1976, Izv. Krym. Astrofiz. Obs., 55, 112.

Lyubimkov L.S., 1984, Astrofizika, 20, 475.

Lyubimkov L.S., 1988, Astrofizika, 29, 479.

Lyubimkov L.S., 1996, Astrophys. Space Sci, 243, 329.

Lyubimkov L.S., 1998, Astron. Zh., 75, 61 (also Astron. Rep, 42, 52).

Lyubimkov L.S., Lambert D.L., Rachkovskaya T.M., Rostopchin S.I., Tarasov A.E., Poklad D.B., Larionov V.M., Larionova L.V., 2000, Mon. Not. Roy. Astron. Soc., 316, 19 (Paper I),

Lyubimkov L.S., Rachkovskaya T.M., Rostopchin S.I., Lambert D.L., 2002, Mon. Not. Roy. Astron. Soc., 333, 9(Paper II).

Lyubimkov L.S., Rostopchin S.I., Lambert D.L., 2003, Mon. Not. Roy. Astron. Soc. (in press, Paper III).

Maeder A., Meynet G., 2000, Ann. Rev. Astron.Astrophys., 38, 143.

Meynet G., Maeder A., 2000, Astron. Astrophys., 361, 101.